To the reader:
The Skywatcher's Diary for March 2000 has been prepared by Robert C. Victor.
Credit to the author and to Abrams Planetarium,
Department
of Physics and Astronomy at Michigan
State University, and mention of our Sky
Calendar, would be appreciated.
A sample issue of the Sky Calendar is available over the Internet.
It can be viewed via the World-Wide Web at
http://www.pa.msu.edu/abrams/SkyCalendar/Index.html
If you would like a printed sample of the March issue, please send a
long, self-addressed stamped envelope to:
March Sky Calendar
Abrams Planetarium
Michigan State University
East Lansing, MI 48824
Each month, the Department of Physics and Astronomy at Michigan State
University makes the Skywatcher's Diary available over the Internet. It
can be accessed at http://www.pa.msu.edu/abrams/SkyWatchersDiary/Diary.html
Current and back-issues of the Skywatcher's Diary are available in our
archives at
http://www.pa.msu.edu/abrams/SkyWatchersDiary/Archives.html
ftp://www.pa.msu.edu/pub/swd/
Shrinking gathering of evening planets: Jupiter, brightest evening
star, is in WSW to W at dusk, sinking lower as month progresses. Saturn
is 10 to 6-1/2 degrees upper left of Jupiter. Mars closes from 19
degrees to within 3 degrees lower right of Jupiter this month. The three
bright outer planets take up 25 degrees on March 6, 20 degrees on March
13 & 14, and 15 degrees on March 21 & 22, 10 degrees on March 29
& 30. Each clear evening an hour after sunset, check on the changing
arrangement of Mars-Jupiter-Saturn. At same time, Moon can be followed
for 14 consecutive evenings, March 7-20. Watch the young waxing crescent
Moon climb past the three bright outer planets March 7-10. Moon pulls alongside
Mars on March 8, alongside Jupiter March 9, and climbs to upper left of
Saturn on March 10. Moon continues eastward and appears near one of the
five first-magnitude zodiacal stars on evenings of March 11, 14, 17. On
March 19, Sun and Full Moon are simultaneously just above opposite horizons
about 10-15 minutes before sunset. March 20 is final day of 2-week interval
when Moon can be seen an hour after sunset. On March 21 & 22, the gathering
of three bright outer planets is 15 degrees long, with Jupiter shining
midway between Mars and Saturn. The gathering will become even more impressive
next month, shrinking to only 5 degrees across in mid-April. That will
be the most compact visible gathering of these three planets over a 179-year
interval, from December 1901 until November 2080. The April Sky Calendar
will highlight this rare trio.
Morning planets: Venus rises in ESE to E in twilight, one hour
before sun up on March 1, to 35 minutes before sunup on March 31, from
lat. 40 degrees N. So Venus becomes harder to see, but remains easy to spot from
southern US. where it rises earlier. Mercury passes above Venus
at midmonth; see Diary.
Skywatcher's Diary: March 2000
Please note: In Skywatcher's Diary, morning events are described
on the previous date.
Wednesday, March 1
Check the western sky nightly at dusk to follow the gathering of three
naked-eye planets as it gets more compact in coming weeks. Jupiter in WSW
is the brightest of the three, outshining even Sirius, the brightest star,
in SSE. Tonight Saturn is within 10 degrees upper left of Jupiter, while
fainter Mars is within 19 degrees to Jupiter's lower left. The gathering
spans 28 degrees tonight, shrinking to just 5 degrees across by mid-April.
A small telescope shows Saturn's rings, now tipped 20 degrees from edge-on,
and up to four of Jupiter's moons.
Venus, the brightest planet, is visible in the morning, but with increasing
difficulty as this month progresses. About 45 minutes before sunrise on
Thursday, look for Venus just risen in ESE, about 17 degrees lower left
of the waning crescent Moon. Check again on Friday and Saturday, as the
Moon goes past. Today Mercury passes inferior conjunction, on the near
side of the Sun, and is lost in the solar glare. Around mid-month, if you
can still find Venus in bright twilight, a pair of binoculars may show
Mercury passing closely above it.
Thursday, March 2
About 45 minutes before sunrise on Friday, look very low in ESE. There
you will find the last easy-to-see thin old crescent Moon, with Venus just
rising about 6 degrees lower left.
Friday, March 3
Here's a sight for binoculars 20 minutes before sunrise on Saturday: A very
thin old Moon rising in ESE in bright morning twilight, about 6 degrees
lower left of Venus. Observers in southern states, where Venus and Moon
rise earlier in a darker sky, will have an easier view.
Saturday, March 4
If you're fortunate enough to be in a place with no interference from man-made
lights, then your sky is probably dark enough at nightfall to detect the
zodiacal light.
About 1-1/2 hours after sunset, face west and look for a huge, softly luminous
cone of light with its base near the horizon and its axis near the lineup
of three planets then visible. The light should certainly appear to engulf
Mars, now 32 degrees from the Sun. Does its faint outer portion extend
as high as Saturn, now 58 degrees, or to Aldebaran, 85 degrees from Sun?
The brightening crescent Moon will begin to interfere on Wednesday evening,
but beginning on March 22, the sky at nightfall will again be moonless.
Zodiacal light is from sunlight scattered by cometary and asteroidal dust
particles in the inner solar system, concentrated near the plane of the
ecliptic.
Sunday, March 5
The Moon is New tonight, at 7:17 p.m. in Hawaii, 9:17 p.m. PST on the West
Coast, and 12:17 a.m. EST Monday morning on the East Coast. If you spot
the Moon shortly after sunset on Monday evening, calculate the time elapsed
since New. Casual observers will easily spot the Moon on Tuesday evening.
More on Monday and Tuesday.
Monday, March 6
Beginning about 20 minutes after sunset, if the sky is very clear, use
binoculars to scan just above the horizon about 10 degrees south of west
for a hairline-thin very young Moon. The Moon's age (time elapsed since
New) is about 18 hours from the East Coast, 21 hours from West Coast, and
nearly 24 hours from Hawaii. The best chance to spot the crescent will
be in the Southwest U.S. and Hawaii, where the Moon sets later, in a darker
sky. If you miss the Moon, look again tomorrow evening. Meanwhile, as twilight
deepens, look for the lineup of three planets in the west: Bright Jupiter,
with Saturn 9 degrees upper left, and faint Mars 16 degrees lower right.
Three planets within 25 degrees, and closing!
Tuesday, March 7
For most of the U.S., this evening is the first easy chance to see the
young Moon. By 45 minutes after sunset, the thin crescent is easy to see,
low, just south of west. As the sky darkens, note the display of all three
bright outer planets above: Faint Mars about 11 degrees above the Moon,
bright Jupiter 15 degrees upper left of Mars, and Saturn 9 degrees upper
left of Jupiter. Watch the Moon climb past all three bodies by Friday evening.
Wednesday, March 8
The nearly 3-day old crescent Moon with three planets is a striking sight
in the western sky an hour after sunset. Look for faint Mars about 6 degrees
to the Moon's right, bright Jupiter about 12 degrees above the Moon, and
Saturn 9 degrees upper left of Jupiter.
Thursday, March 9
Tonight an hour after sunset, the crescent Moon floats 5 degrees left of
Jupiter and about 7 degrees below Saturn, as seen from central U.S. Look
for faint Mars 14 degrees lower right of Jupiter.
Friday, March 10
An hour after sunset, the crescent Moon, about one-quarter illuminated,
is well up in WSW. Jupiter, the brightest evening star, shines to the Moon's
lower right, with Saturn about midway between. Aldebaran, eye of Taurus
the Bull, twinkles to Moon's upper left. Note the lineup, in order from
lower right to upper left, of Mars-Jupiter-Saturn-Moon-Aldebaran.
Saturday, March 11
An hour after sunset, as seen from central U.S., the reddish star Aldebaran,
eye of the Bull, is just 5 degrees to Moon's upper left. (From western U.S.,
they're even closer.) Binoculars give a fine view of the Hyades star cluster
in the same field. With first-magnitude Aldebaran, these stars complete
the V-shaped head of Taurus. Check hourly until moonset, and watch the
Moon creep toward Aldebaran and pass some of the Hyades stars.
Sunday, March 12
An hour after sunset, the nearly half-full Moon is high in the SW, almost
at First Quarter phase. Note Aldebaran some 9 or 10 degrees to Moon's lower
right.
Mornings this week, about 45 to 40 minutes before sunrise, aim binoculars
at the horizon some 15 degrees south of east, and watch for the rising
of Mercury and Venus. From northern states, theyre hard to see in bright
twilight. On Monday they're 4 degrees apart, with Mercury upper left of
Venus. On Thursday March 16, Mercury will pass just over 2 degrees above
Venus. These two inner planets are easier to see from southern states,
where they rise earlier, in a darker sky.
Monday, March 13
The Moon, now past First Quarter phase and just over half full, is high
in S to SSW an hour after sunset. The reddish star Betelgeuse, marking
Orion's shoulder, is 14 degrees to Moon's lower right.
Tuesday, March 14
The waxing gibbous Moon is high in SSE an hour after sunset. The Gemini
twins Pollux and Castor, 4-1/2 degrees apart, are about 10 to 12 degrees
to Moon's upper left. Procyon, in Canis Minor the Lesser Dog, is 16 degrees
below the Moon. In the west, the lineup of Mars-Jupiter-Saturn has shrunk
to 20 degrees long.
Wednesday, March 15
Note the alignment of Moon-Pollux-Castor high in the SSE an hour after
sunset. Bright Procyon is 17 degrees to Moon's lower right. About 40 minutes
before sunrise, aim binoculars at the horizon 15 degrees south of east,
and try for Mercury and Venus. On Thursday, Mercury passes 2.2 degrees
above Venus.
Thursday, March 16
An hour after sunset, look for Regulus, heart of Leo, in ESE about 13 degrees
to Moon's lower left.
Friday, March 17
This evening look for Regulus, heart of Leo the Lion, very close to the
Moon, just two days before Full. Binoculars will help you spot the star
in the Moon's glare. An hour after sunset from eastern and central U.S.,
Moon and star are within 2 degrees apart.
Saturday, March 18
An hour after sunset, Moon is in E to ESE, with Regulus about 15 degrees
upper right.
Sunday, March 19
If you have unobstructed views of the horizon toward east and west, you
can see Sun and Moon simultaneously just above opposite horizons 10-15
minutes before sunset this evening. The Moon is Full tonight, at 11:44
p.m. EST. Spring begins less than three hours later, at 2:35 a.m. EST on
Monday, March 20.
Monday, March 20
This evening the Moon rises almost due east, about 40-45 minutes after
sunset. This week, the Moon will rise farther south each night, over an
hour later each evening for the next few nights from places north of lat.
40 degrees north. Three hours after sunset tonight, the first-magnitude
star Spica in Virgo is in ESE about 12 degrees below the Moon. By an hour
before sunup on Tuesday, Moon is WSW, with Spica 9 or 10 degrees to its
lower left.
Tuesday, March 21
In the west this evening and Wednesday, the gathering of three bright outer
planets is 15 degrees long, with Jupiter shining midway between Mars and Saturn.
The gathering will become even more impressive next month, shrinking to
only 5 degrees across in mid-April. That'll be the most compact visible gathering
of these three planets over a 179-year interval, from December 1901 until
November 2080. The April Sky Calendar will highlight this rare trio.
The largest minor planet or asteroid Ceres, of magnitude 6.9, is at
opposition tonight, and is visible in binoculars 11 degrees E of Denebola,
Leo's tail, and about 7 degrees WNW of Epsilon in Virgo. If you try for
Ceres tonight, observe right at nightfall, before the Moon rises and brightens
the sky. You can use a finder chart for Ceres on page 109 of the March
issue of Sky & Telescope magazine.
Three hours after sunset tonight, the Moon is in ESE, with Spica 7 degrees
to its right. By an hour before sunrise on Wednesday, theyre in SW to WSW.
Wednesday, March 22
Three hours after sunset, the waning gibbous Moon, just risen, is about
14 degrees south of east and 17 degrees lower left of Spica.
Thursday, March 23
The daily sky diagrams on the Abrams Planetarium Sky Calendar makes
following the Moon and planets easy and fun. Subscriptions are $9.00 per
year, starting anytime, from Abrams Planetarium, Michigan State University,
East Lansing, MI 48824. Sky Calendar is also one of the benefits of membership
in the Friends of Abrams Planetarium (a one-year Individual Membership,
tax-deductible, is $25 per year; other categories are available). The April
issue will show a rare compact gathering of Mars, Jupiter, and Saturn.
Friday, March 24
An hour before sunrise on Saturday, the Moon is in S to SSW, with reddish
Antares, heart of the Scorpion, about 8 degrees lower left.
Saturday, March 25
On Sunday, an hour before sunrise, the Moon is two-thirds full in the south,
with Antares, heart of Scorpius, 12 degrees lower right. Look about half
an hour earlier on Monday and Tuesday, before the sky brightens, and you'll
find the Teapot of Sagittarius below the Moon, which passes Last Quarter
phase between those two mornings.
Sunday, March 26
This evening, the gathering of three bright outer planets is low in the
west an hour after sunset. Their lineup is 12 degrees long, with Saturn
7 degrees upper left of bright Jupiter, and Mars 5 degrees to Jupiter's
lower right.
Monday, March 27
On Tuesday Mercury reaches greatest elongation, or its maximum angular
distance from the Sun, 28 degrees. But this is a poor appearance from mid-northern
latitudes, with Mercury between E and ESE just 2 degrees up in mid-twilight,
as seen from lat. 40 degrees N. The Sun is then 9 degrees below the horizon,
almost 45 minutes before sunrise. Observers in southern US., and better
yet, the tropics and southern latitudes, will have an easier view. Using
binoculars 35 minutes before sunrise, try for Venus rising 8 degrees to
Mercury's lower left.
Tuesday, March 28
The winter constellation Orion the Hunter is still prominent in early spring,
in SW an hour after sunset. Note Orion's shoulder Betelgeuse about 10 degrees
above the belt, and Rigel, the Hunter's foot, 9 degrees below. Extend the
belt 22 degrees southeastward (to the left) to the Dog Star Sirius, brightest
nighttime star, and the same distance northwest (right) to Aldebaran, eye
of Taurus the Bull. Procyon completes the nearly equilateral Winter Triangle,
about 26 degrees on a side, with Sirius and Betelgeuse. More on Wednesday.
Wednesday, March 29
Mentioned here yesterday were five of winter's bright stars, which will
all disappear between late April and early June. In order of disappearance,
they are Rigel, Aldebaran, Sirius, Betelgeuse, and Procyon. Look for these
stars each clear evening within an hour after sunset, and determine the
last day you see each one before it sinks into the bright western evening
twilight.
Thursday, March 30
Low in the west an hour after sunset, all three bright outer planets lie
in a short line just 10 degrees long. Bright Jupiter lies between the other
two, about two-thirds of the way from Saturn toward Mars.
Friday, March 31
Low in west an hour after sunset, Saturn is 6-1/2 degrees upper left of
Jupiter, and Mars less than 3 degrees to Jupiter's lower right. We'll watch
these three planets converge into a rare gathering just 5 degrees apart
in mid-April.